Many Americans consume low amounts of calcium, which places them at risk for several major diseases. However, little is known about the factors that control calcium ingestion. The goal of the proposed research is to investigate which peripheral nerves and brain areas control calcium intake in rats. Ultimately, this may help to provide insight into why animals, including humans, select certain levels of calcium in their diets and how this behavior might be altered to prevent disease. Three experiments will be conducted, with specific aims as follows: 1) to determine whether particular brain areas are more active when calcium appetite is induced, using immunocytochemistry to detect c-Fos, c-Jun, and FosB; 2) to determine whether lesions of the subfornical organ affect calcium intake; 3) to determine whether transection of the chorda tympani and/or glossopharyngeal nerve affects short-term intake of CaCl2 and other solutions.